Method of flame-cutting metal plates and forming shaped edges thereon



' June- Z2, 1948. J. H. RouNTRl-:E 2,443,710

METHOD OF FLAME CUTTING METAL PLATES AND FORMING SHAPED EDGES THEREONFiled Apriles, 1945 Y l .W 30 444 INVENTOR JOHN H. ROUNTREE I V l lATTORNEY Patented June 22, 1948 UNITED STATES ATENT OFFICE METHOD OFFLAME-CUTTING METAL PLATES AND FORMING SHAPED EDGES THEREON John H.Rountree, Plainfield, N. J., assignor to The Linde Air Products Company,a corporation of Ohio 11 Claims.

This invention generally relates to the art of cutting metal by animproved oxygen cutting method and in particular relates to cutting,beveling and squaring edges of relatively thick steel plates, or thelike, by such method, although the purview of the invention in itsbroader aspects includes the application of the method to the cutting ofvarious shapes of steel or metal members, where it is desired to impartcertain predetermined edge contours thereto. The method is particularlyadapted for use in the sizing and shaping of rolled homogeneous armorplate for subsequent welding operations.

Heretofore, in the preparation of plate members for subsequent weldingoperations, it has been customary to utilize conventional tractortype,straight line and template following contour shape cutting machines, andwhen these machines were equipped with the usual type cutting equipmentincluding a single standard cutting blowpipe, operations were limited tocutting a single edge face in one pass. The particular size and shape ofplate members having been cut out, one or more beveling operations wereusually desirable so that the edges oi the plate might be given aplurality of faces, with a view toward efficient butt welding, and so insuch operations a plurality of passes were necessary.

Subsequently, cutting of a plurality of faces, usually including atleast one beveled face and an unbeveled nose face, was accomplished inthe preparation of such plate member edges, by an improved method termedmulti-faced cutting. This method involved the use of a series of cuttingnozzles incorporated in a suitably arranged fixture and so arranged that`a required edge contour composed of a plurality of faces could be cutwith a single passage of the cutting equipment. Such equipmentconventionally included a group or cluster of nozzles, each arranged atpredetermined angles to the others, oxygen and acetylene gas supplyingequipment therefor and plate riding equipment on the Work with means forrelating the same to a proper line of contour.

However, in the use of such equipment adapted for multi-faced cutting ina single pass, it has been found that in the preparing of relativelythick steel plates, such as one inch in thickness or greater forsubsequent welding operations, by forming the edges with a double beveland an intermediate unbeveled nose face, difficulties have beenencountered due to the squaring-off jet being deected by the scrap sideof the under bevel kerf wall and resulting in the formation of gouges inthe under bevel face. It has been 2 found that the more heat that isdissipated from the zone of the under bevel kerf Walls, the more dilcultit is t`o make intersecting cuts therethrough. Such difficulties areparticularly encountered when the angle of the kerf forming the lower orunder bevel is equal to or less than 45, since, when the `angle ofintersection is more acute, there is more likelihood that the followingjet will re-enter the kerf wall of a preceding jet; when the angle ofintersection is greater than 45, preheating presents the majordiiiiculty as there is a tendency :for the preheating flames to bedeflected..

Accordingly, the principal objects of the present invention are toprovide a high speed and accurate method of oxygen cutting plate edgesto form a predetermined multi-faced contour; to arrange a group ofconnected cutting nozzles so that an improved sequence of cuts isattained in plate edge preparation; to provide, in such operations, anauxiliary cut, thereby to produce a heated metal iin or membrane, whichfin, before its removal creates a heated area within the limits of whicha second cut is made; to provide in such cutting operations such aheated fin so that a squaring cut may be made therethrough withoutdeflection of the oxygen jet utilized in making such squaring cut, intoa bevel cut already made; to provide a new and improved series of cutsin such plate edge preparation, so that cuts intersecting within theupper and lower limits of the plate may readily be utilized. These andother objects of the invention Will become apparent from the followingdescription taken in connection with the accompanying illustrationlgures, which are not to be deemed limitative thereof.

In the drawing:

Fig. 1 is an end elevation of a cutting fixture including four cuttingnozzles each adjustably positioned in respect to the other, a plateriding attachment and control means therefor, and a steel work plate,indicated partially;

Fig. 2 is a side elevation of Fig. 1;

Fig. 3 semi-diagrammatically illustrates in section a series of kerfsand a desired edge contour in respect to a steel plate;

Fig. 4 semi-diagrammatically illustrates in section the result of anattempt to produce the cuts illustrated in Fig. 3, showing the deectionof cutting oxygen from a desired line of cut by a kerf already made,with resultant gouging of a kerf wall of the latter;

Fig. 5 semi-diagrammatically illustrates a method of attaining thedesired edge contour illustrated in Fig. 3, by employing an auxiliarykerf, to provide a heated membrane or n through which the squaring cutcan be made without deflection.

Fig. 6 seini-diagrammatically illustrates a particularly advantageousapplication of the principle ofl the invention to an under bevel kerfhaving an angle of greater than 45.

The essence of the invention resides in making a preliminary andauxiliary kerf in the scrap metal outside of the final plate edge beingprepared, which auxiliary kerf serves to prevent the dissipation of heatby conduction to the scrap, and then making an inner adjacent kerfapproximately parallel thereto. By virtue of the heat thus applied andconserved in cutting such two mutually non-intersecting kerfs throughthe plate and forming a heated metal iinv or membrane between thesekerfs, the making o-f additional planar squaring or beveling kerfs whichextend through the said iin, or adjacent thereto, is -greatlyfacilitatedand accelerated, without tending to deflect the oxygen jet orjets utilized in making such latter kerfs, into formerly madeintersecting kerfs.

Referringto the drawings, a xture B holding a cluster of cuttingnozzlesi, I2,` I4, and l will preferably be adjustably and slidablyarranged in a conventional man-ner, as indicated, relative to a centralbracket member I8. These nozzles will normally be of the usual type,each supplying a, mixture ofoxygen and acetylene for one or morepreheating names, and also adapted to supply a central jet of oxygen forcutting through the metal body. l In the cutting process, an exothermicreaction is ordinarily set up between the heated metal and the oxygen.The central bracket member I may be controlled by an overhead guide arm2Q which guide arm will be normally guided by an orthodox tractor-typestraight line or template following contour shape cutting machine (notshown). Also, central bracketmember` I8 may be arranged with a dependingspacing arm 22 which latter at its lower end is provided with a platefollower wheel 2li thus providing a conventional plate riding assemblyin thistype of apparatus. The nozzles IE, I2, IG, and I6, as indicatedparticularly in Fig. 2, are arranged to cut concurrently but insequence, one following the other, along the adjacent parallel paths onthe same surface of a steel plate. thus to give a plate or plate membera desired shape and size, and also to. give a particular multi-facededge contour, as desirable or required for subsequent butt weldingoperations.

The apparatus of Figs. 1 and 2 includes a group or cluster B of nozzlesII), I2, I 4, and I wherein nozzles I2 yand It are each directed andarranged in a conventional manner to cut kerfs 26 and 28, thus providinglower and upper bevelfaces 32 and 30, and furthermore wherein nozzle I4is arranged to cut a perpendicular kerf 34, thus to provide a square orunbeveled nose face 3,6 upon steel plate 33 as indicated in Fig. 3. Withthis arrangement it is usual for nozzle I2 to lead and make the rst kerfidentified as 25; for nozzle I4 to follow and make the second kerfidentied as 34; and for nozzle I5 to trail and form the lastkerLidentied as 28. However, in conducting this type of operation,thecutting oxygen jet from nozzle I4 usually is deflected by the underbevel kerf 2B already cut by nozzle I2, with the result that the lowerbevel face 32 is gouged out` as indicated at 33 in Fig, 4, or may bepitted andscarred dependent upon the speed of operation.

Accordingly, the invention in this particular embodiment involvescutting an auxiliary kerf til (see Fig 5 particularly) by the cuttingoxygen jet discharged from the auxiliary cutting nozzle it which isplaced in leading position, ahead of nozzle, I2, and otherwise nozzlesi2, it, and i6 follow the sequence described above. The auxiliary kerfd@ provides an. intermediate isolated membrane or n Q2 in the waste orscrap metal identified as fill; also the kerf prevents the dissipationof heat from membrane d2 into waste metal t#otherwise normally flowablethereto by conduction. Since membrane i2 lies between kerfs fit-and t@in plate 36, it will be realized that considerable heat is applied andconserved in said auxiliary metal membrane or n [52, maintaining thesame at a temperature at which it is moreeasily penetrated in cuttingthe squaring Keri-,34.

In other words, the existence of membrane ft2 sufficiently retardsthedissipation, by conduction, ofthe exothermic heat so that the membranemetal is v,at a great enough temperature for ready cutting-with theresult that the tendency for the deiiection of the oxygen jet emanatingfrom nozzle itin cutting kerf .'tfi, is eliminated, or sufiicientlyminimized so that it will not interfere with the production of aproperly iinished edge face 32.

Fig. 5 may be. said toillustrate a relatively thick, two` (2) inch steelplate of rolled hornogeneous armor plate stock wherein amriliary kerfdi! is separated from subsequent kerf Z6 by onequarter (1/4) tothree-eighths of an inch, although the latter distance ordinarily willVary dependent upon the speed of operation and the volume of oxygen inthe cutting jet. it will be noted that in' this instance said lierfs lidand 26 are indicated as being in approximately parallel planes. It iswithin the concept of this invention that'` the auxiliary kerf di) mayconceivably accomplish a useful purpose, as for example the cutting'of akerf for a second adjacent plate of metal being prepared, and it isunderstood that such an embodiment of the invention is within the scopeorv the 4appended claims.

InFig. 6, a particular adaptation of my invention is illustrateddiagrammatically, and particularly pertains to the cutting of a wideangle under .bevel kerl, namely, as illustrated, an angle of greaterthan 45. In describing this iigure common reference numerals have beenutilized to designate common parts or lerfs as above described inconnection with Figs. 1 5. Such wide angle `keri's are relatively moretime consuming inasmuch as they require a greater thickness of metal tobe cut, and therefore may be said to allow greater time for thedissipation oi heat into the scrap metal; accordingly, since themarginal portions of the scrap are less heated, such marginal portionspresent a greater barrier to the penetration of the oxygen jet emanatingfrom the nozzle i@ in cutting kerf Sri. Accordingly, in cutting suchmultiefaced edge contours as illustrated in'l'lig. 6, an auxiliarycutting nozzle il) will be usedto form an auxiliary Keri t@ whichprecedes kerf The oxygen cutting streams discharged by `nozzles It andl2 desirably are spaced apart inthe direction of their advance alongtheirparallel paths on the plate surface, with the cutting stream fromnozzle le in a leading position with respect to the following cuttingstreamfrom nozzle i2; and these streams are directed` obliquely againstthe plate surface duringsuch advance, either in substantially paralleldirections as illustrated by Fig.v 5 or in divergent directions asillustrated by Fig. 6.

As stated hereinabove, the invention has wide application in respect vtothe preparation oi the edges of relatively thick steel platesparticularly for subsequent welding operations, by forming such edgeswith appropriate multi-faced surfaces, especially edges with a doublebevel and an intermediate unbeveled nose face. l-iowever, in its widestpurview the invention has possible applicationin the art of cuttingmetal where an auxiliary kerf is made in the scrap for preventing thedissipation of heat by conduction into the main body of scrap whether ornot an exothermc reaction is set up between the cutting medium and theworkpiece, and it is obvious that the invention is applicable to cuttingoperations inu volving various shapes and sizes of steel plates. platemembers and other members, and that the same as described may be variedto include al ternative metal cutting operations. since certaindescribed procedures may be reM placed in whole or in part by otherprocedures and certain features utilized in part, without departing fromthe spirit and scope of my invention, reference is therefore to be hadto the appended claims for a definition thereof.

I claim:

1. A method of cutting a metal plate to form thereon a shaped edgecomposed of at least two angularly related faces, which method comprisesconcurrently advancing two oxygen cutting streams along adjacentparallel paths on the same surface of said plate while maintaining saidcutting streams positioned relatively to each other to cut two mutuallynon-intersecting kerfs through said plate, to form one of such faces andalso to provide a heated metal membrane between said two kerfs; andadvancing another oxygen cutting stream behind and concurrently withsaid two cutting streams and along a path on said surface of said plateparallel to and laf erally spaced from the portion of said surfacebetween said adjacent parallel paths while angularly positioning saidother cutting stream relatively to said two cutting streams to cut akerf in said plate to form 'another of such faces and also to cut a kerfthrough said heated membrane and thereby inhibit deection of said othercutting stream against the face previously formed by one of said twocutting streams.

2. A method of cutting a metal plate as defined in claim 1 wherein saidtwo oxygen cutting streams are maintained spaced apart the longitudinaldirection of said adjacent paths.

3. A method of cutting a metal plate as defined in claim l, wherein saidtwo oxygen cutting streams are maintained in spaced relationlongitudinally of said adjacent paths, to provide a leading cuttingstream and a following cutting stream, said leading cutting stream beingpositioned and advanced to cut vone of said non-intersecting kerfsthrough said plate to thereby rst form one side of said membrane, andsaid following cutting stream being positioned and advanced to cutthrough said plate the other of said non-intersecting keris to therebysubsequently form said one of said faces and the opposite side of saidmembrane.

4. A method of cutting a metal plate as de ned in claim 1, wherein saidtwo oxygen cutting streams are directed obliquely against the sainesurface of said plate, and said other oxygen cutting stream is directedperpendicularly against said surface.

Accordingly,

5. A method of cutting a metal plate as defined in claim 1, wherein saidtwo oxygen cutting streams are directed obliquely and in substantiallyparallel directions against the same surface of said plate.

6. A method of cutting a metal plate as dened in claim l, wherein saidtwo oxygen cutting streams are directed obliquely and in divergentdirections against the same surface of said plate.

7. A method of cutting a metal plate as defined in claim i, wherein saidtwo oxygen cutting streams are directed obliquely and in sub--stantially parallel directions against the same surface of said plate,and said other oxygen cutting stream is directed perpendicularly againstsaid surface,

il. A method of cutting a metal plate as defined in claim 1, whereinsaid two oxygen cutting streams are directed obliquely and insubstantially parallel directions against the same surface of saidplate, and said other oxygen cutting stream is directed obliquelyagainst said surface.

9. A method of cutting a metal plate as defined in claim 1, wherein saidtwo oxygen cutting streams are directed obliquely and in divergentdirections against the same surface of said plate, and said other oxygencutting stream is directed perpendicularly against said surface.

l0. A method of cutting a metal plate to form thereon a shaped edgecomposed of three angularly related faces, which method comprisesconcurrently advancing two leading oxygen cutting streams along adjacentparallel paths on the same surface of said plate while maintaining saidcutting streams positioned relatively to each other to out two mutuallynon-intersecting kerfs through said plate, to form one of said threefaces and also to provide a heated metal membrane between said twokeris; and advancing two other oxygen cutting streams behind andconcurrently with said two leading cutting streams and along paths onsaid surface of said plate parallel to and spaced from the portion ofsaid surface between said adjacent parallel paths while angularlypositioning said other cutting streams relatively to each other andrelatively to said two leading cutting streams to cut kerfs in saidplate to form the other two of said three faces and also to cut kerfsthrough said heated membrane and thereby inhibit deflection of cuttingoxygen against the face previously formed by one of said two leadingcutting streams.

ll. A method of cutting a metal plate to form thereon a shaped edgecomposed of two angularly related faces, which method comprisesconcurrently advancing two oxygen cutting streams along adjacentparallel paths on the same surface of said plate while maintaining saidcutting streams positioned relatively to each other to out two mutuallynon-intersecting kerfs through said plate, to form one of said two facesand also to provide a heated metal membrane between said two kerfs; andadvancing a third oxygen cutting stream behind and concurrently withsaid two cutting streams and along a path on said surface of said plateparallel to and spaced from the portion of said surface between saidadjacent parallel paths while angularly positioning said third cuttingstream relatively to said two cutting streams to cut a kerf in saidplate to form the other of said two faces and also to cut a, kerfthrough said heated membrane and thereby inhibit deflection of saidthird cutting 7 8 stream against the face previously formed by oneNumber Name Date of said two cutting streams. 1,787,247 Grow Dec. 3D,1930 JOHN H. ROUNTREE. 2,146,255 MOSS Feb. 7, 1939 2,184,562 RockefellerDec. 26, 1939 REFERENCES CITED 5 2,202,130 Wagner May 28, 1940 Thefollowing Yeferences are of record in the 21,271,613 Babcock et al' Feb3 1942 me of this patent: 2,288,026 Rea June 30, 1942 2,293,853 RountreeAug, 25, 1942 UNITED STATES PATENTS Number Name Date 10 1,684,692Bucknam Jan. 20, 1914 1,554,468 Cobelly Sept. 22, 1925 OTHER REWRENCESRockefeller, Shaping Edges for Welding, Steel Magazine, March 11, 1940,pages 60, 61, 62, 64.

